The most widely used part of the Internet is the World Wide Web, often abbreviated “WWW” or simply referred to as just “the Web.” The Web is an Internet service that organizes information through the use of hypermedia. Hypermedia documents that are accessible over the Web, or Web pages, present information on a myriad of topics.
FIG. 1 illustrates an example configuration 100 of devices through which a user may access Web pages over the Web. According to example configuration 100, client device 102, which includes Web browser 104 and display device 106, is connected to network 110. Also connected to network 110 is server device 120, which includes Web server 122. Web server 122 has access to information for Web page 124.
To access Web page 124, a user of client device 102 directs Web browser 104 to request Web page 124. Web browser 104 sends a request to view Web page 124 via network 110 to Web server 122 on server device 120. Web server 122 receives the request and sends the information for Web page 124 to client device 102. Web browser 104 interprets the information for Web page 124 and then causes Web page 124 to be displayed on display device 106. The user may browse for additional Web pages by selecting links that are embedded in Web page 124. Selecting such links causes Web browser 104 to issue requests for information corresponding to the links from appropriate Web servers.
According to established Internet custom, users may access many Web pages without charge. One way that Web page providers (“providers”) make money from Web pages that users view without charge is by including paid advertisements in the pages. Such advertisements generally include links to Web pages containing information on advertised products or services. If a provider has more than one advertisement available to display on a particular Web page, the provider may attempt to select an advertisement for display that is in line with the viewing user's interests. Tailoring the content of advertisements to user interests increases the probability that the user will select the advertised links.
Providers can determine the interests of users in many ways, e.g., through information provided by the user in a user profile, by observing the browsing history of the user, by observing search queries performed by the user, etc. A provider may record such interest information and refine the information over time to tailor content presentation to the interests of the users more accurately.
One way that Web page providers record the interests of users is through Internet “cookies”. A cookie is a string that a Web server may cause to be stored on a client device. Through a cookie, the Web server may store information on the client machine. The client device automatically returns the cookie to the Web server when the client requests information from the server. For example, when a user on client device 102 views Web page 124, Web server 122 may provide a cookie to client device 102 along with the requested data. Web browser 104 returns the cookie with future requests to Web server 122. Web server 122 may include, in a cookie on client device 102, the Web pages that a particular user of client device 102 views. The interests of the user may be inferred from this list of Web pages.
Thus, a Web server may track various indicia of user interest through cookies. However, because cookies are stored on client machines, a Web server cannot access cookie information about a particular user stored at one client machine when that particular user views Web pages from a second client machine. Also, users have the option of clearing all stored cookies from a client machine, which reduces the effectiveness of storing user interest data in cookies.
Furthermore, the content of a cookie may become increasingly large as data is gathered about the user and stored in the cookie. Client machines that are capable of accessing the Internet are becoming smaller with more limited resources, i.e., smart phones, personal digital assistants (PDAs), etc. Transferring and storing bulky cookies on such small devices can reduce the speed with which these devices can process Web pages.
Another way to tailor the presentation of content to the interests of a particular user is to maintain a history of user interest in a database. For example, a provider of Web content that is interested in tailoring presented content to the interests of a user may request that the user create and fill out a user profile. Then, the provider may track information about the user through the user profile and employ that information in selecting content to provide to the user. For example, the provider may record the Web pages that the user views when the user is logged into the user profile, infer the interests of the user from the Web pages that the user views, and select content based on those inferred interests.
Additionally, a provider may analyze trends in information gathered through a multitude of user profiles, or other information sources, to determine rules to govern the determination of user interest in particular topics. For example, a provider may perceive a trend that indicates that people who view Web pages about cars are generally also interested in soft drinks. Providers may use the information gathered through the user profiles as well as the rules based on information trends to tailor the presentation of content to individual users.
However, databases that store such information are generally large and complex, and it may be expensive to extract and analyze the information. Also, if a user fails to log into her corresponding user profile when the user browses the Internet, the provider cannot connect the user with the user's profile. Thus, the utility of gathering information about the user through profiles is limited. Furthermore, tracking user interest in this manner can cause a large amount of data to be transferred between client machines and servers, which can cause performance problems on small devices such as smart phones and PDAs, as described above.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.